Patent application title: MULTIPLE ROW SCALABLE LED-UV MODULE

Abstract:

An LED-UV lamp that is easily interchangeable within a UV-curing process
and scalable in length with a fine resolution so that it is easily
customizable to any UV-curing application. The LED-UV lamp may
incorporate multiple rows of LEDs and contain corresponding optics that
effectively deliver radiant power to a substrate at distances of several
inches.

Claims:

1. A UV LED lamp, comprising:a connection end cap with electrical and
fluid connections and alignment pins;a cross over end cap; anda lamp body
disposed between said connection end cap and said cross over end cap and
having a first plurality of LEDs emitting UV radiation, a first reflector
positioned to reflect and focus UV radiation from said first plurality of
LEDs onto a substrate, and a heat sink to absorb heat generated by said
LEDs.

2. The UV LED lamp of claim 1, further comprising a second plurality of
LEDs and a second reflector positioned to reflect and focus UV radiation
from said second plurality of LEDs onto said substrate.

3. A UV LED lamp, comprising:a pair of end caps;a heat sink mounted
between said end caps;a first plurality of LED subassembly segments
mounted to a first surface of said heat sink; anda reflector positioned
to reflect and focus radiation of the LED subassembly segments onto a
substrate,wherein said first plurality of LED subassembly segments can be
varied in number to accommodate a variable width or length of said
substrate.

4. The UV LED lamp of claim 3, further comprising a second plurality of
LED subassembly segments mounted to a second surface of said heat sink,
wherein said second plurality of LED subassembly segments can be varied
in number to accommodate said variable width or length of said substrate.

5. The UV LED lamp of claim 4, wherein said second plurality of LED
subassembly segments emits a radiation wavelength differing from a
radiation wavelength of said first plurality of LED subassembly segments.

6. The UV LED lamp of claim 3, further comprising a plurality of alignment
pins extending from one of said end caps.

7. The UV LED lamp of claim 3, further comprising a pair of fluid valves
for admitting coolant to ingress and egress said heat sink.

8. The UV LED of claim 7, wherein said heat sink defines a pair of coolant
passages, wherein one of said coolant passages admits coolant ingressing
said heat sink and wherein the other of said coolant passages admits
coolant egressing said heat sink.

9. The UV LED of claim 7, wherein each of said coolant passages is bounded
by fin features protruding into said liquid coolant.

10. A method of configuring a UV LED lamp for UV-curing of a substrate
surface, said method comprising:selecting a first plurality of LED
subassembly segments to accommodate a length or a width of said substrate
surface; andplacing said plurality of selected LED subassembly segments
within said UV LED lamp.

11. The method of claim 10, further comprising:selecting a second
plurality of LED subassembly segments to accommodate said length or said
width of said substrate surface; andplacing said plurality of selected
LED subassembly segments within said UV LED lamp.

12. The method of claim 10, further comprising positioning a reflector to
reflect UV radiation emitted from said LED subassembly segments to said
substrate surface.

13. The method of claim 12, wherein said LED subassembly segments are
attached to a heat sink having a pair of coolant passages.

14. The method of claim 12, further comprising disposing said reflector
and LED subassembly segments between a pair of end caps.

15. A method of curing materials deposited on a substrate, said materials
having UV photoinitiators, such method comprising directing UV radiation
at said substrate, said UV radiation originating from the UV LED lamp of
claim 1.

16. A method of curing materials deposited on a substrate, said materials
having UV photoinitiators, such method comprising directing UV radiation
at said substrate, said UV radiation originating from the UV LED lamp of
claim 3.

17. A method of curing materials deposited on a substrate, said materials
having UV photoinitiators, such method comprising directing UV radiation
at said substrate, said UV radiation originating from the UV LED lamp of
claim 4.

18. The method of claim 17, wherein a different material is cured by each
of said subassemblies, such subassemblies emitting differing wavelengths
of UV radiation.

19. The method of claim 17, further comprising cooling said UV subassembly
segments.

20. The method of claim 19, wherein said UV subassembly segments are
cooled by circulating coolant through a pair of coolant passages located
in said heat sink.

[0003]The present invention relates to LED-UV lamps. More particularly,
the invention is suitably used in the application of UV-curing of inks,
coatings, and adhesives having UV photo initiators therein.

[0004]2. Background

[0005]UV LED lamps are permanently mounted within the UV-curing process.
Depending upon the optics used, the UV LED lamps can be required to be
located at a specific distance from the substrate so that uniformity and
intensity are optimized.

[0006]Some UV LED lamps are scalable in length with coarse resolution.

[0007]UV LED lamps are mounted into a UV-curing process in a manner that
makes them difficult and time consuming to remove for cleaning,
maintenance, or the like. UV LED lamps are mounted in fixed positions
within the UV-curing process where the location within the position is
often determined by the process machinery into which the UV curing LED
lamps are being integrated.

[0008]Different positions within the UV-curing process could require the
UV LED lamps to be at different locations with respect to the substrate.
A conflict could arise between the location required by the optics of the
lamp and the location determined by the machinery of a UV-curing process
which scenario could render the UV LED lamp unsuitable for placement in
particular positions within a UV-curing process.

[0009]If a lamp is required at an alternate location, either an existing
lamp must be uninstalled from an existing location and reinstalled at the
desired location which option would only be suitable if the location
required by the optics of the UV LED lamp is compatible with the location
available in the desired position, or a new lamp must be purchased
possibly with redesigned optics. UV LED lamps of different wavelength
would also not be easily interchangeable.

[0010]The coarse resolution in length scalability could result in the
scenario where the lamp length options that are available are either too
short or too long for a particular application which may make the UV LED
lamps difficult or impossible to install into some UV-curing
applications. For example, if the length of a UV LED lamp was scalable in
3 inch increments, and a 40 inch lamp was required, the options would
either be 39 inches (13×3 inches), or 42 inches (14×3
inches). The 39 inch lamp would be too short and could result in uncured
product at the ends of the lamp. The 42 inch lamp could be too long to
fit into the envelope that is available within the UV-curing process.

SUMMARY OF THE INVENTION

[0011]LEDs are mounted onto short subassembly segments that may be
produced in assorted lengths which segments are then easily mounted into
the LED-UV module in a row running along the length of the module.

[0012]Assembling the LEDs in segments that are easily mounted into the
LED-UV module would simplify the process of LED replacement and possibly
make the process less expensive. If an LED fails, the segment whereon the
failed LED had been assembled can be disconnected, removed, and then a
new segment can be installed in its place.

[0013]The LEDs may degrade as they get older and their output power may
decrease below an acceptable level for their application. In this case
the owner of the LED-UV lamp would have the option of replacing the
segments with new ones as opposed to replacing the whole module.

[0014]LEDs are solid state semiconductor devices. The efficiency and power
output of LEDs can increase from one generation to the next as scientific
breakthroughs are made and manufacturing processes improve. The owner of
the LED-UV module would have the option to easily upgrade the module by
swapping out old segments for new ones with improved operating
characteristics.

[0015]Providing the segments in an assortment of lengths could enable the
length of the row of segments to be scalable with a finer resolution than
what may be possible if all of the segments where the same length, while
at the same time the total number of parts required to assemble the row
of LEDs could be reduced. For example, the segments could be configured
in a 3 inch version, a 4 inch version, and a 6 inch version. A 12 inch
row of segments could then be assembled by connecting 2 of the 6 inch
segments. A 13 inch row of segments could be assembled by connecting a 6
inch segment, a 4 inch segment, and a 3 inch segment. A 14 inch row of
segments could be assembled by connecting a 6 inch segment and two 4 inch
segments. The row of LEDs could be assembled in a variety of lengths with
a 1 inch resolution. On the other hand, if only one segment was made, in
a 3 inch version for example, the resolution of the possible LED row
lengths would be 3 inches, resulting in fewer length options available
for customizability. The segment could be made in a 1 inch version to
achieve a 1 inch resolution, but doing so could increase the complexity
of the assembly by increasing the number of parts required to construct a
row.

[0016]The main module body contains a surface extending the length of the
module, whereon the LED segments can be mounted.

[0017]This surface provides correct positioning and easy mounting of the
LED segments.

[0018]The main module body contains an integral heat sink feature with
coolant passages that run the length of the module and are positioned
such that they pass near the surface whereon the LED segments mount.

[0019]The heat sink feature provides a simple means of effectively
extracting heat from the LEDs. This maintains the LED junction
temperature at an acceptably low level thus maximizing the life of the
LEDs.

[0020]The module is designed so that it is interchangeable and can
therefore be quickly and easily installed into or removed from docking
ports that are rigidly mounted into a UV-curing process without the use
of tools.

[0021]Interchangeability allows the modules to be easily removed from the
UV-curing process for cleaning, repair, maintenance, or the like. LED-UV
modules of different wavelengths can be installed into the UV-curing
process and the modules can be moved between different locations within
the UV-curing process as long as there is a docking port available.
Removal and installation of the LED-UV modules from the associated
docking ports within a UV-curing process is a tool-less procedure and can
be done by a person of no extraordinary skill.

[0022]All necessary connections (e.g. power, communication, liquid
cooling) are made automatically upon installation of the LED-UV module
into a docking port, and then disconnected automatically during the
removal of the LED-UV module from a docking port.

[0023]Automatic engaging and disengaging of the connections between the
LED-UV module and the docking port upon insertion and removal of the
LED-UV module ensure that the connections are made properly, save time,
and make the overall operation of the UV-curing process more convenient
for the user.

[0024]All connection devices (e.g. electrical pins, coolant valves) are
positioned such that they do not protrude beyond the outer surfaces of
the LED-UV module.

[0025]Designing the connections such that they do not protrude beyond the
outer surfaces of the module protects them from damage. With the LED-UV
module being designed in a manner that the module is easily removable
from the UV-curing process, the possibility of damage to the connections
that could result from handling the module will be significantly reduced.

[0026]The LED-UV module can incorporate a common optical design using a
parabolic or elliptical trough reflector that allows for varying
distances and mounting locations with respect to the substrate being
cured without a significant loss of uniformity or optical (irradiant)
intensity.

[0027]LEDs, by themselves, typically exhibit a Lambertian radiation
pattern in which the intensity of the light output by the LED chip is
directly proportional to the cosine of the angle between the point of
observation and the surface normal of the LED chip. An elliptical or
parabolic trough reflector can effectively gather the light and project
it onto a substrate that is positioned at varying distances (i.e. from
fractions of an inch to several inches) from the base of the LED-UV
module with a minimal loss in intensity and in a very uniform manner.

[0028]Without the use of a reflector, the LED-UV module may need to be
placed at either a fixed, optics-dependent distance from the substrate or
much closer to the substrate than would be allowable by some UV-curing
processes or some positions within a UV-curing process. One example could
be in a sheet-fed printing press. In sheet-fed printing, it is typically
desirable to locate one or more LED-UV modules immediately following the
application of one or more UV-curable inks following the inking units of
the printing machine in order to "pin" or "dry" the UV-curable inks or
spot varnishes prior to the application of a UV-curable coating at the
end of the press prior to the delivery of sheets onto a pile. For inking
unit curing locations (immediately following the inking units), it would
be desirable to locate the LED-UV modules closer (typically 1 to 3
inches) to the substrate for the benefit of easier mechanical mounting in
order to fit within the space constraints provided by various makes and
models of printing machines. However, at end-of-press curing locations,
the method of sheet transfer provided by most printing machines prohibits
closer mechanical location through the end-of-press sheet delivery area
and would require the LED-UV module to be mounted as far as 3 to 5 inches
away from the substrate. If the LED-UV module were placed too close to
the substrate it would collide with the moving machinery of the printing
press. The use of reflector style optics enables a single,
interchangeable design of the LED-UV module of the invention to be placed
in multiple docking or mounting positions at differing distances to the
substrate without significant loss of optical uniformity or radiant
intensity within a UV-curing process that would otherwise have
inaccessible or impractical mounting locations and/or require multiple,
non-interchangeable optical designs of the LED-UV modules between the
various positions of the process.

[0029]The LED-UV modules would be available in a variety of UV wavelengths
and each wavelength module would be interchangeable with the others and
could therefore be applied to any docking port within the UV-curing
process.

[0030]Different types of UV curable products can cure most effectively
when irradiated by different wavelengths of UV light. For example, clear
products may cure most effectively with longer wavelength UV light, while
darker, more heavily pigmented products may cure more effectively with
shorter wavelength UV light. Overall system performance may be maximized
by the ability to interchange LED-UV modules of different wavelength
within the UV-curing process depending upon the preferences of the
UV-curable product that is being cured.

[0031]The LED-UV module could incorporate multiple, adjacent, parallel
rows of LEDs where each row shines into a corresponding trough reflector.

[0032]Incorporating multiple, adjacent, parallel rows of LEDs where each
row shines into a corresponding trough reflector would increase the
radiant power output by the LED-UV module by a factor equal to the number
of rows of LEDs. A single lamp of this embodiment could have the same
radiant power output as multiple lamps of the single row embodiment with
the added advantages of lower cost and smaller form factor compared to
multiple lamps of the single row embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is an isometric view of one embodiment of the LED-UV module
of the invention.

[0034]FIG. 2a is a top view of the embodiment of FIG. 1.

[0035]FIG. 2b is a side view of the embodiment of FIG. 1.

[0036]FIG. 2c is an end view of the embodiment of FIG. 1.

[0037]FIG. 3 is a cross section view of the embodiment of the LED-UV
module shown in FIGS. 1 and 2 along line A-A of FIG. 2b.

[0038]FIG. 4 is a perspective view of one embodiment of an LED segment
assembly of the invention.

[0039]FIG. 5 is a cross sectional view of one embodiment of the
application of a trough reflector to aid in the transference of UV light
from the LEDs onto the substrate.

[0040]FIG. 6 is an isometric view of another embodiment of the LED-UV
module of the invention incorporating a plurality of adjacent, parallel
rows of LEDs and multiple trough reflectors.

[0044]FIG. 8 is a cross section view of the embodiment of the LED-UV
module shown in FIGS. 6 and 7a-c along line A-A of FIG. 7b.

[0045]FIG. 9 is an illustration of one embodiment of the application of a
plurality of trough reflectors to aid in the transference of UV light
from the LEDs onto the substrate and to multiply the available radiant
power.

[0046]It is understood that the above-described figures are only
illustrative of the present invention and are not contemplated to limit
the scope thereof.

DETAILED DESCRIPTION OF THE INVENTION

[0047]The following is a description of possible embodiments of the LED-UV
module of the invention. The examples and figures that follow are
intended to teach a person skilled in the art how to effectively design
and implement the present invention, but are not intended to limit the
scope of the invention. The features and methods disclosed in the
detailed description may be used separately or in conjunction with other
features and methods to provide improved devices of the invention and
methods for making the same. The features and methods disclosed in this
detailed description may not be necessary to practice the invention in
the broadest sense, but are provided so that a person of skill in the art
may further understand the details of the invention.

[0048]Another description of the LED-UV lamp of this invention, as well as
a docking system accommodating such lamp, is present in U.S. patent
application Ser. No. ______, with Attorney Docket No. 1013.09US02,
entitled Interchangeable UV LED Curing System, and filed concurrently
with this application, the entire disclosure of such application hereby
incorporated by reference.

[0049]Referring to FIGS. 1, 2a-c, and 3, an LED-UV module 100 is shown
having electrical connections 102, coolant valves 104, a module body 106,
a module cover 108, a connection end cap 110, a cross-over end cap 112,
alignment pins 114, a transparent cover 116, a trough reflector 118,
coolant passages 120, LED segments 122, and a surface 124 on the module
body 106 to mount the LED segments 122.

[0050]The electrical connections 102 would be located on the connection
end 126 of the LED-UV module 100 and may be mounted onto the connection
end cap 110. To protect the electrical pins 102 from damage during
handling of the LED-UV module 100, the electrical connections 102 could
be mounted to the connection end cap 110 in a recessed fashion so that
they do not protrude beyond the outer surfaces of the connection end cap
110. The electrical connections 102 would be used to transfer power and
possibly communications from the LED-UV module 100 to mating electrical
connections that would be present in the docking ports within the
UV-curing process. The electrical connections could be pin and socket
type connections.

[0051]The coolant valves 104 would be located on the connection end 126 of
the LED-UV module 100 and may be mounted onto the connection end cap 110.
To protect the coolant valves 104 from damage during handling of the
LED-UV module 100, the coolant valves 104 could be located on the
connection end cap 110 such that they do not protrude beyond the outer
surfaces of the connection end cap 110. The coolant valves 104 would
connect to mating coolant valves that would be present in the docking
port and would provide a supply and return for cooling fluid to flow
through the LED-UV module 100. The coolant valves 104 and the mating
coolant valves in the docking port could be spring actuated poppet style
valves that would automatically be pushed open when they are engaged, and
automatically spring closed when they are disengaged.

[0052]The module body 106 would be the main supporting component of the
LED-UV module 100. Two significant features on the module body 106 could
be the surface 124 that locates the LED segments 122, and the coolant
passages 120. The module body 106 could support one edge of the
transparent cover 116. The module body 106 could be made of an extrusion
out of a material that is a good heat conductor such as aluminum.

[0053]The module cover 108 would serve as the final component of the
LED-UV module 100 assembly and cover all of the internal components. The
module cover 108 could contain a feature that would hold the trough
reflector 118 in the correct position and shape. The module cover 108
could support one edge of the transparent cover 116. The module cover 108
could be made of an extrusion and the material could suitably be the same
as the material of the module body 106.

[0054]The connection end cap 110 would serve as the mounting structure for
the electrical connections 102, coolant water valves 104, and the
alignment pins 114. The connection end cap 110 would mount to the
appropriate end of the module body 106 forming the connection end 126 of
the LED-UV module 100. Power and communications would pass through the
connection block 110 into the inside of the LED-UV module 100 through the
electrical connections 102. Liquid coolant would flow between the coolant
valves 104 and the coolant passages 120 at the interface 128 where the
connection block 110 mounts to the module body 106. This interface may be
sealed by a gasket such as an o-ring to prevent liquid coolant from
leaking at the interface 128.

[0055]The cross-over end cap 112 would mount to the end of the module body
106 that is opposite the connection block 110 forming the cross-over end
130 of the LED-UV module 100. The cross-over end cap would contain a
passage that would connect one of the coolant passages 120 to the other
thus forming a circuit for liquid coolant to flow into the LED-UV module
100 through one of the coolant valves 104, through one of the water
passages 120, through the passage in the cross-over end cap 112 through
the other of the water passages 120, and then out of the LED-UV module
100 through the other of the coolant valves 104. The interface 132
between the cross-over end cap 112 and the module body 106 could be
sealed with a gasket such as an o-ring to prevent liquid coolant from
leaking at the interface 132.

[0056]The alignment pins 114 would be located on the connection end of the
LED-UV module and may be mounted to the connection block 110. The
alignment pins 114 could serve to align the connections 102, 104 prior to
their engagement with the mating connections present in the docking port.

[0057]The transparent cover 116 would most suitably be made of a durable
material that would be highly UV transparent such as quartz, glass,
acrylic, or the like. The transparent cover 116 would serve as a
protective window that would protect the internal components of the
LED-UV module while allowing the light generated by the LEDs to pass
through the transparent cover. The transparent cover could be supported
on one edge by the module body 106 and supported on the opposite edge by
the module cover 108. The ends 134 of the transparent cover 116 could be
trapped by the connection end cap 110 on one end and the cross-over end
cap 112 on the other.

[0058]The reflector 118 would be made of a highly UV reflective material
such as acrylic mirror, polished metal, or the like, and could be formed
into shape prior to installation into the LED-UV module 100. The
reflector 118 could be held in position and shape by a mating feature in
the module cover 108. The reflector could be trough shaped and may
incorporate a parabolic or elliptical geometry that would transfer the UV
light emitted by the LEDs onto the substrate.

[0059]The coolant passages 120 would run the length of the module body 106
and be positioned so that they pass near the surface 124 whereon the LED
segments 122 mount. The coolant passages 120 facilitate the removal of
heat generated by the LEDs and may be dimensioned and located such that
the temperature of the module body 106 is essentially uniform over a
length of such module. Heat generated at the P/N junctions of the LEDs is
conducted from the LED segments 122, into the module body 106 where it is
transferred to the liquid coolant by means of convection at the surfaces
of the coolant passages 120. The coolant passages could contain fin
features 136 that protrude into the liquid coolant. The fin features 136
would serve to increase the convective surface area of the coolant
passages 120 as well as generate turbulence in the liquid coolant that
would increase the associated convection coefficient. The fin features
could also increase the rate of heat conduction through the module body.
The presence of fin features 136 in the coolant passages 120 would serve
to increase the rate of heat convection from the module body 106 to the
liquid coolant, ultimately resulting in lower LED junction temperatures.
Lower LED junction temperatures could enable longer LED lifetimes.

[0060]One embodiment of an LED segment 122 is shown in FIG. 4. The LED
segment 122 could consist of a heat transfer plate 138, a plurality of
LED packages or segments 140, thermal interface material 142, and
fasteners 144 to attach the LED packages 140 to the heat transfer plate
138. The LED packages 140 could be off-the-shelf packages or they could
be custom designed. The LED package 140 specifications could suitably be
low thermal resistance, high powered UV output, and quick disconnect
power terminals 146. The LED segment 122 could contain mounting features
such as bolt holes 148 to enable fastening to the module body 106 in a
manner that maximizes heat transfer from the LED segment 122 to the
module body 106. Multiple LED segments 122 could suitably be mounted to
the module body in a lengthwise, end-to-end configuration to form a long
row of LEDs. The LED segments 140 would be designed in a manner that
maximizes the LED line density (i.e. number of LEDs per inch) and the LED
segments 140 could be designed in an assortment of lengths which would
enable finer length resolution when assembling the LED segments 140 in a
lengthwise, end-to-end configuration to form a long row of LEDs. The
finer length resolution would facilitate customizability for a variety of
different length UV-curing applications. Providing the segments 140 in an
assortment of lengths could enable the length of the row of segments 140
to be scalable with a finer resolution than what may be possible if all
of the segments 140 were the same length, while at the same time the
total number of parts required to assemble the row of LEDs could be
reduced. For example, the segments 140 could be configured in a 3 inch
version, a 4 inch version, and a 6 inch version. A 12 inch row of
segments 140 could then be assembled by connecting 2 of the 6 inch
segments. A 13 inch row of segments 140 could be assembled by connecting
a 6 inch segment, a 4 inch segment, and a 3 inch segment. A 14 inch row
of segments 140 could be assembled by connecting a 6 inch segment and two
4 inch segments. The row of LED segments 140 could be assembled in a
variety of lengths with a 1 inch resolution. On the other hand, if only
one segment 140 was made, in a 3 inch version for example, the resolution
of the possible LED row lengths would be 3 inches, resulting in fewer
length options available for customizability. The segment 140 could be
made in a 1 inch version to achieve a 1 inch resolution, but doing so
could increase the complexity of the assembly by increasing the number of
parts required to construct a row.

[0061]FIG. 5 illustrates how the implementation of a trough reflector 118
could effectively transfer light 150 from the LEDs onto a substrate 152
at a distance 154 of several inches. This type of optical configuration
would be very suitable for UV-curing applications wherein it is not
possible to place the LED-UV module in close proximity to the substrate.

[0062]Some UV-curing applications may require more UV power than an LED-UV
module 100 having a single row of LED segments 122 can provide. An
alternative embodiment of the LED-UV module 100 of the invention could
consist of two or more adjacent, parallel rows of LED segments 122
shining into separate trough reflectors 118.

[0063]Referring to FIGS. 6, 7a-c, and 8, an LED-UV module 200 is shown
having electrical connections 202, coolant valves 204, a first module
cover 206, a second module cover 208, a connection end cap 210, a
cross-over end cap 212, alignment pins 214, a transparent cover 216, a
plurality of trough reflectors 218, coolant passages 220, LED segments
122, a heat sink 224, and surfaces 226 on the heat sink 224 to mount the
LED segments 122.

[0064]The electrical connections 202 would be located on the connection
end 228 of the LED-UV module 200 and may be mounted onto the connection
end cap 210. The electrical connections 202 would be used to transfer
power and possibly communications from the LED-UV module 200 to mating
electrical connections that would be present in the docking ports within
the UV-curing process. The electrical connections could be pin and socket
type connections.

[0065]The coolant valves 204 would be located on the connection end 228 of
the LED-UV module 200 and may be mounted onto the connection end cap 210.
To protect the coolant valves 204 from damage during handling of the
LED-UV module 200, the coolant valves 204 could be located on the
connection end cap 210 such that they do not protrude beyond the outer
surfaces of the connection end cap 210. The coolant valves 204 would
connect to mating coolant valves that would be present in the docking
port and would provide a supply and return for cooling fluid to flow
through the LED-UV module 200. The coolant valves 204 and the mating
coolant valves in the docking port could be spring actuated poppet style
valves that would automatically be pushed open when they are engaged, and
automatically spring closed when they are disengaged.

[0066]The first module cover 206 would cover one side of the LED-UV module
200. The first module cover 206 could contain a feature that would hold
one of the trough reflectors 218 in the correct position and shape and
the first module cover 206 could support one edge of the transparent
cover 216. The first module cover 206 could be made of an extrusion out
of a material such as aluminum or plastic.

[0067]The second module cover 208 would cover the other side of the LED-UV
module 200. The second module cover 208 could contain a feature that
would hold another of the trough reflectors 218 in the correct position
and shape and the second module cover 208 could support the other edge of
the transparent cover 216. The second module cover 208 could be made of
an extrusion out of a material such as aluminum or plastic.

[0068]The connection end cap 210 would serve as the mounting structure for
the electrical connections 202, coolant water valves 204, and the
alignment pins 214. The connection end cap 210 would mount to the
appropriate end of the LED-UV module 200 forming the connection end 228
of the LED-UV module 200. Power and communications would pass through the
connection block 210 into the inside of the LED-UV module 200 through the
electrical connections 202. Liquid coolant would flow between the coolant
valves 204 and the coolant passages 220 at the interface 230 where the
connection block 210 mounts to the heat sink 224. This interface may be
sealed by a gasket such as an o-ring to prevent liquid coolant from
leaking at the interface 230.

[0069]The cross-over end cap 212 would mount to the end of the LED-UV
module 200 that is opposite the connection block 210 forming the
cross-over end 232 of the LED-UV module 200. The cross-over end cap 212
would contain a passage that would connect one of the coolant passages
220 to the other thus forming a circuit for liquid coolant to flow into
the LED-UV module 200 through one of the coolant valves 204, through one
of the water passages 220, through the passage in the cross-over end cap
212 through the other of the water passages 220, and then out of the
LED-UV module 200 through the other of the coolant valves 204. The
interface 234 between the cross-over end cap 212 and the module body 206
could be sealed with a gasket such as an o-ring to prevent liquid coolant
from leaking at the interface 234.

[0070]The alignment pins 214 would be located on the connection end of the
LED-UV module and may be mounted to the connection block 210. The
alignment pins 214 could serve to align the connections 202, 204 prior to
their engagement with the mating connections present in the docking port.

[0071]The transparent cover 216 would most suitably be made of a durable
material that would be highly UV transparent. The transparent cover 216
would serve as a protective window that would protect the internal
components of the LED-UV module while allowing the light generated by the
LEDs to pass through the transparent cover 216. The transparent cover 216
could be supported on one edge by the first module cover 206 and
supported on the opposite edge by the second module cover 208. The ends
234 of the transparent cover 216 could be trapped by the connection end
cap 210 on one end and the cross-over end cap 212 on the other.

[0072]The reflectors 218 would be made of a highly UV reflective material
and could be formed into shape prior to installation into the LED-UV
module 200. The reflectors 218 could be held in position and shape by
mating features in the first and second module covers 206 and 208. The
reflectors 218 could be trough shaped and may incorporate a parabolic or
elliptical geometry that would transfer the UV light emitted by the LEDs
onto the substrate.

[0073]The coolant passages 220 would run the length of the heat sink 224
and be positioned so that they pass near the surface 226 whereon the LED
segments 122 mount. The coolant passages 220 facilitate the removal of
heat generated by the LEDs. Heat generated at the P/N junctions of the
LEDs is conducted from the LED segments 122, into the heat sink 224 where
it is transferred to the liquid coolant by means of convection at the
surfaces of the coolant passages 220. The coolant passages could contain
fin features 238 that protrude into the liquid coolant. The fin features
238 would serve to increase the convective surface area of the coolant
passages 220 as well as generate turbulence in the liquid coolant that
would increase the associated convection coefficient. The fin features
238 could also increase the rate of heat conduction through the module
body. The presence of fin features 238 in the coolant passages 220 would
serve to increase the rate of heat convection from the heat sink 224 to
the liquid coolant, ultimately resulting in lower LED junction
temperatures. Lower LED junction temperatures could enable longer LED
lifetimes.

[0074]FIG. 9 illustrates how the implementation of a plurality of trough
reflectors 218 could effectively transfer light 240 from the multiple,
adjacent, parallel rows of LEDs onto a substrate 242 at a distance 244 of
several inches. This type of optical configuration would be very suitable
for UV-curing applications wherein it is not possible to place the LED-UV
module in close proximity to the substrate and where the power of
multiple LED-UV lamps 100 is required in a single location.

[0075]The LED-UV modules 100, 200 of the invention could be produced in an
assortment of models where each model would have a different peak
wavelength, or could have a plurality of peak wavelengths, in its
spectral output depending on the LEDs used in the LED segments 122. To
achieve a plurality of peaks in the spectral output of the LED-UV modules
100,200, a mixture of LEDs of different UV wavelength could be used, in
an alternating pattern, within each LED segment 122. A single LED-UV
module 100,200 with a single peak wavelength in its spectral output is
contemplated to be within the spirit and scope of this invention.
Additionally, a single LED-UV module 100,200 with a plurality of peak
wavelengths in its spectral output is contemplated to be within the
spirit and scope of this invention.

[0076]Having different models of LED-UV modules 100,200 available, each
with a different peak wavelength output, or emitting a plurality of peak
wavelengths, and where the LED-UV modules 100,200 are interchangeable
within a UV-curing process would increase the flexibility of the
UV-curing system. Many LED-UV lamps are available in an assortment of UV
wavelengths and some with the option of multiple peaks in their spectral
output. The LED-UV modules 100,200 of this invention would be designed
such that they can be quickly inserted into and removed from a UV-curing
process without the use of tools provided that the associated docking
ports are mounted into the UV-curing process. A model of an LED-UV module
100,200 of one UV spectral output can be removed and a model of a
different UV spectral output can be inserted in a matter of minutes by a
person of no extraordinary skill.

[0077]A person of ordinary skill in the art will readily appreciate that
individual components shown on various embodiments of the present
invention are interchangeable to some extent and may be added or
interchanged on other embodiments without departing from the spirit and
scope of this invention.

[0078]Because numerous modifications of this invention may be made without
departing from the spirit thereof, the scope of the invention is not to
be limited to the embodiments illustrated and described. Rather, the
scope of the invention is to be determined by the appended claims and
their equivalents.